package com.cdutetc.demo.repository;

import java.util.List;
import java.util.Optional;

import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Repository;

import com.cdutetc.demo.entity.User;

// 用于操纵底层数据
@Repository
public interface UserRepository extends JpaRepository<User,Long> {
    
    Optional<User> findByUsername(String username);


    
}
